Published patent application US2008/0273323A1 discloses a specific luminaire design to emit light which is experienced by users as pleasant. The luminaire comprises a main light source and an additional light source. The additional light source emits light of a color spectrum that is different from the color spectrum of the main light source. Light of the main light source and of the additional light source are mixed before being emitted through the main light exit window of the luminaire. Further, a portion of the light emitted by the additional light source is guided to a side or a rear side of the luminaire in order to be emitted through an additional light exit window on said side or said rear side of the luminaire. Such a luminaire provides an opportunity to emit white light through the main light exit window and also to emit light of a different color, for example blue light, via the additional light exit window. To some extent, this provides a skylight experience because white light and, possibly, blue light are emitted. However, if a viewer looks towards the luminaire, irrespective of the viewing angle, the luminaire is perceived as a white light emitting luminaire and the area around it (the roof or the wall) is perceived as a blue light reflective area. A skylight in a roof provides, on sunny days, a directed light beam of sunlight, and blue light in other directions. Thus, the viewer who looks towards the skylight and who is inside the directed light beam of sunlight sees a white skylight, while viewers outside the directed light beam see a blue skylight. In other words, the luminaire of the cited patent application provides a limited skylight experience.
Further, the luminaire according to the cited patent application has a complicated structure and requires a relatively large number of optical elements, such as, at least two light sources which each emit light of a different color distribution, a means to mix the light of both light sources, and a light guiding structure to guide light of the additional light source towards the additional light exit window. Thus, the known luminaire for creating an attractive light emission is relatively expensive.